{ sources ? import ./sources.nix

, pkgs ? import sources.nixpkgs {

    overlays = [ (import sources.rust-overlay) ];

  }

, rust-overlay ? pkgs.rust-bin.stable.latest.default

}:

  with pkgs;

  mkShell {

    name = "build";

    buildInputs = [

        # cargo tooling

        cargo-deny

        cargo-watch

        # hard dependencies

        cmake

        openssl

        pkgconfig

        rust-overlay

    ];

  }

{ sources ? import ./sources.nix

, pkgs ? import sources.nixpkgs {

    overlays = [ (import sources.rust-overlay) ];

  }

}:

let

  stable = pkgs.rust-bin.stable.latest.default;

  rust-overlay = stable.override {

    extensions = [ "rust-src" "rust-analysis" ];

  };

  devault = (pkgs.callPackage ./default.nix {});

in

  with pkgs;

  mkShell {

    name = "development";

    buildInputs = devault.buildInputs ++ [

        gcc

        ripgrep

        rust-analyzer

    ];

  }

{

    "niv": {

        "branch": "master",

        "description": "Easy dependency management for Nix projects",

        "homepage": "https://github.com/nmattia/niv",

        "owner": "nmattia",

        "repo": "niv",

        "rev": "723f0eeb969a730db3c30f977c2b66b9dce9fe4a",

        "sha256": "0016l7230gd2kdh0g2w573r9a2krqb7x4ifcjhhsn4h1bwap7qr0",

        "type": "tarball",

        "url": "https://github.com/nmattia/niv/archive/723f0eeb969a730db3c30f977c2b66b9dce9fe4a.tar.gz",

        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"

    },

    "nixpkgs": {

        "branch": "release-21.11",

        "description": "Nix Packages collection",

        "homepage": "",

        "owner": "NixOS",

        "repo": "nixpkgs",

        "rev": "2766f77c32e171a04d59b636a91083bae862274e",

        "sha256": "1xk1f62n00z7q5i3pf4c8c4rlv5k4jwpgh0pqgzw1l40vhdkixk9",

        "type": "tarball",

        "url": "https://github.com/NixOS/nixpkgs/archive/2766f77c32e171a04d59b636a91083bae862274e.tar.gz",

        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"

    },

    "rust-overlay": {

        "branch": "master",

        "description": "Pure and reproducible nix overlay of binary distributed rust toolchains",

        "homepage": "",

        "owner": "oxalica",

        "repo": "rust-overlay",

        "rev": "e17bfe3baa0487f0671c9ed0e9057d10987ba7f7",

        "sha256": "1kg6kfkc115gcip69vrxz74ryfmh44fdx2480l6qahkgl0d3pzxb",

        "type": "tarball",

        "url": "https://github.com/oxalica/rust-overlay/archive/e17bfe3baa0487f0671c9ed0e9057d10987ba7f7.tar.gz",

        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"

    }

}

# This file has been generated by Niv.

let

  #

  # The fetchers. fetch_<type> fetches specs of type <type>.

  #

  fetch_file = pkgs: name: spec:

    let

      name' = sanitizeName name + "-src";

    in

    if spec.builtin or true then

      builtins_fetchurl { inherit (spec) url sha256; name = name'; }

    else

      pkgs.fetchurl { inherit (spec) url sha256; name = name'; };

  fetch_tarball = pkgs: name: spec:

    let

      name' = sanitizeName name + "-src";

    in

    if spec.builtin or true then

      builtins_fetchTarball { name = name'; inherit (spec) url sha256; }

    else

      pkgs.fetchzip { name = name'; inherit (spec) url sha256; };

  fetch_git = name: spec:

    let

      ref =

        spec.ref or (

          if spec ? branch then "refs/heads/${spec.branch}" else

          if spec ? tag then "refs/tags/${spec.tag}" else

          abort "In git source '${name}': Please specify `ref`, `tag` or `branch`!"

        );

      submodules = spec.submodules or false;

      submoduleArg =

        let

          nixSupportsSubmodules = builtins.compareVersions builtins.nixVersion "2.4" >= 0;

          emptyArgWithWarning =

            if submodules

            then

              builtins.trace

                (

                  "The niv input \"${name}\" uses submodules "

                  + "but your nix's (${builtins.nixVersion}) builtins.fetchGit "

                  + "does not support them"

                )

                { }

            else { };

        in

        if nixSupportsSubmodules

        then { inherit submodules; }

        else emptyArgWithWarning;

    in

    builtins.fetchGit

      ({ url = spec.repo; inherit (spec) rev; inherit ref; } // submoduleArg);

  fetch_local = spec: spec.path;

  fetch_builtin-tarball = name: throw

    ''[${name}] The niv type "builtin-tarball" is deprecated. You should instead use `builtin = true`.

        $ niv modify ${name} -a type=tarball -a builtin=true'';

  fetch_builtin-url = name: throw

    ''[${name}] The niv type "builtin-url" will soon be deprecated. You should instead use `builtin = true`.

        $ niv modify ${name} -a type=file -a builtin=true'';

  #

  # Various helpers

  #

  # https://github.com/NixOS/nixpkgs/pull/83241/files#diff-c6f540a4f3bfa4b0e8b6bafd4cd54e8bR695

  sanitizeName = name:

    (

      concatMapStrings (s: if builtins.isList s then "-" else s)

        (

          builtins.split "[^[:alnum:]+._?=-]+"

            ((x: builtins.elemAt (builtins.match "\\.*(.*)" x) 0) name)

        )

    );

  # The set of packages used when specs are fetched using non-builtins.

  mkPkgs = sources: system:

    let

      sourcesNixpkgs =

        import (builtins_fetchTarball { inherit (sources.nixpkgs) url sha256; }) { inherit system; };

      hasNixpkgsPath = builtins.any (x: x.prefix == "nixpkgs") builtins.nixPath;

      hasThisAsNixpkgsPath = <nixpkgs> == ./.;

    in

    if builtins.hasAttr "nixpkgs" sources

    then sourcesNixpkgs

    else if hasNixpkgsPath && ! hasThisAsNixpkgsPath then

      import <nixpkgs> { }

    else

      abort

        ''

          Please specify either <nixpkgs> (through -I or NIX_PATH=nixpkgs=...) or

          add a package called "nixpkgs" to your sources.json.

        '';

  # The actual fetching function.

  fetch = pkgs: name: spec:

    if ! builtins.hasAttr "type" spec then

      abort "ERROR: niv spec ${name} does not have a 'type' attribute"

    else if spec.type == "file" then fetch_file pkgs name spec

    else if spec.type == "tarball" then fetch_tarball pkgs name spec

    else if spec.type == "git" then fetch_git name spec

    else if spec.type == "local" then fetch_local spec

    else if spec.type == "builtin-tarball" then fetch_builtin-tarball name

    else if spec.type == "builtin-url" then fetch_builtin-url name

    else

      abort "ERROR: niv spec ${name} has unknown type ${builtins.toJSON spec.type}";

  # If the environment variable NIV_OVERRIDE_${name} is set, then use

  # the path directly as opposed to the fetched source.

  replace = name: drv:

    let

      saneName = stringAsChars (c: if (builtins.match "[a-zA-Z0-9]" c) == null then "_" else c) name;

      ersatz = builtins.getEnv "NIV_OVERRIDE_${saneName}";

    in

    if ersatz == "" then drv else

      # this turns the string into an actual Nix path (for both absolute and

      # relative paths)

    if builtins.substring 0 1 ersatz == "/" then /. + ersatz else /. + builtins.getEnv "PWD" + "/${ersatz}";

  # Ports of functions for older nix versions

  # a Nix version of mapAttrs if the built-in doesn't exist

  mapAttrs = builtins.mapAttrs or (

    f: set: with builtins;

    listToAttrs (map (attr: { name = attr; value = f attr set.${attr}; }) (attrNames set))

  );

  # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/lists.nix#L295

  range = first: last: if first > last then [ ] else builtins.genList (n: first + n) (last - first + 1);

  # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/strings.nix#L257

  stringToCharacters = s: map (p: builtins.substring p 1 s) (range 0 (builtins.stringLength s - 1));

  # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/strings.nix#L269

  stringAsChars = f: s: concatStrings (map f (stringToCharacters s));

  concatMapStrings = f: list: concatStrings (map f list);

  concatStrings = builtins.concatStringsSep "";

  # https://github.com/NixOS/nixpkgs/blob/8a9f58a375c401b96da862d969f66429def1d118/lib/attrsets.nix#L331

  optionalAttrs = cond: as: if cond then as else { };

  # fetchTarball version that is compatible between all the versions of Nix

  builtins_fetchTarball = { url, name ? null, sha256 }@attrs:

    let

      inherit (builtins) lessThan nixVersion fetchTarball;

    in

    if lessThan nixVersion "1.12" then

      fetchTarball ({ inherit url; } // (optionalAttrs (name != null) { inherit name; }))

    else

      fetchTarball attrs;

  # fetchurl version that is compatible between all the versions of Nix

  builtins_fetchurl = { url, name ? null, sha256 }@attrs:

    let

      inherit (builtins) lessThan nixVersion fetchurl;

    in

    if lessThan nixVersion "1.12" then

      fetchurl ({ inherit url; } // (optionalAttrs (name != null) { inherit name; }))

    else

      fetchurl attrs;

  # Create the final "sources" from the config

  mkSources = config:

    mapAttrs

      (

        name: spec:

          if builtins.hasAttr "outPath" spec

          then

            abort

              "The values in sources.json should not have an 'outPath' attribute"

          else

            spec // { outPath = replace name (fetch config.pkgs name spec); }

      )

      config.sources;

  # The "config" used by the fetchers

  mkConfig =

    { sourcesFile ? if builtins.pathExists ./sources.json then ./sources.json else null

    , sources ? if sourcesFile == null then { } else builtins.fromJSON (builtins.readFile sourcesFile)

    , system ? builtins.currentSystem

    , pkgs ? mkPkgs sources system

    }: rec {

      # The sources, i.e. the attribute set of spec name to spec

      inherit sources;

      # The "pkgs" (evaluated nixpkgs) to use for e.g. non-builtin fetchers

      inherit pkgs;

    };

in

mkSources (mkConfig { }) // { __functor = _: settings: mkSources (mkConfig settings); }

        converge(iter::once(self).chain(remotes.into_iter()))

        self.items.extend(items.into_iter());